Re-loading manuals

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survivor482008

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I have noticed that all manuals that I have read anyway , have different safe starting
loads . Some are 2 to 3 grains different for what I am doing anyway. So my question
what would be best , going with a hotter load from 1 book say 27 grains or start with
the lightest say 25 grains load from the books you have on hand. I know this might seem silly but
being what is involved I thought it a valid querry. Maybe I am just bored. :cheers:
 
I actually just got my manuals in the mail today, Lymans 49th edition and Hornady's 9th edition. I was curious about differences from one manual to the next. Like you I noticed differences in starting loads, but the max loads seem to be consistent in both manuals.

I wouldn't worry about differences in starting loads.
 
There are variables between such things as type of barrel and length of barrel used for data tests,
Plus each little variable component used such as primer and brass type and LOT number of the powder.
Powders can vary in composition slightly between lots and a 2012 lot of powder can have unique but subtle
Diffs from a 2013 lot such as thicker coating of retardent on the kernals or such
This helps explain why one companies data may vary from another
They are all safe In THE LAB but personal mileage may vary depending on your load techniques and firearm
Always start low and work up
 
You may also notice that those loads change over time. Apparently some of the older manuals had higher maximums than is considered politically viable today, for liability reasons. Seems there are quite a few guys who want to shoot at 150% power, for that little bit extra.
 
1 to 3 GR's in a hand gun could be a disaster waiting to happen. In rifle loads 1 to 3 GR's at start loads is not big deal. I have new and old manuals and compare them to each other before I start a load. Better to start with the lower number and work your way up. Handloader Magazine does a revisit of different powders almost every edition the numbers are always changing, some up or down a slight amount from past references.
 
I hear ya OP.
An example dear to my heart comes to mind:
The load for .303 British 174 gr RN from the Hornady 8th edition using H4895 starts at 29.7 grains and goes to a do not exceed of 37.4 gr.
The load for .303 British 174 gr RN from the Lyman 49th edition using H4895 starts at 37.0 grains and goes to a do not exceed of 41.0 gr.
The only realistic variable in this is the primers used. WLR vs Federal 210. Firearms used and barrel length are also variables but not meaningful to me as most reloaders use different rifles and barrel lengths than those specified during testing.

Prudence would dictate starting at a conservative midway point and develop loads specific for each firearm while watching for signs of overpressure. I stop development when I've achieved the desired accuracy, or my gun's safe limits are reached.
 
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Manuals all differ to some degree, you will find some instances of starting loads in one being equal to MAX loads in another... I don't actually even look at starting loads... I cross reference all of my manuals and then start a couple grains below the lowest recorded MAX load, and work up from there... it saves time and powder and is completely safe (at least from a static capacity perspective).
 
Reloading tables remind me of diving tables in that they do not represent a scientifically derived ( and accurately repeatable) law, but rather a record of someone else's experience. They are a guideline. The numbers should all be followed by "ish". Sport divers occasionally forget this, while gazing at the little wrist computer they've been sold, to ill effect.

When working up loads, don't press the limits either way unless/until you can chronograph your shots and understand how to recognize the signs of excessive pressure. Find a "node" within the limits and you'll be a happy camper.
 
The loading manual data is based on their specific rifle/barrel. There is a significant difference between rifles. The only thing that matters is YOUR rifle.

Your rifle might develop more pressure than theirs. This is why you start low and work up. I start a new rifle with 3 rounds in 0.5 gr increments and try to get a feel for where it wants to shoot well and where pressure starts. I am prepared to stop and bring the hotter loads home.
 
When a specific firearm is listed and not a universal receiver and test barrel, then strain gauges are glued to the action and a reference factory load is fired to calibrate the strain gauge. When a strain gauge is used and attached to specific firearms then you will have MORE loading variables. When a test barrel is used minimum chamber and barrel dimensions are used and the loading data may be less for a max load.

On top of this you have the internal capacity of the case and seating depth. Seating a bullet deeper can raise the chamber pressure and seating the bullet closer to the lands can raise pressure. Then you have the different bullet shapes, throat differences etc. My Savage .223 has a longer throat than my AR15 rifles but most loading data for a .223 is with a 1 in 14 or 1 in 12 twist and a short throat.

Below is Quickload data for a .223 Remington with a max rated pressure of 55,000 psi or 52,000 cup. The default setting for case capacity of H2O is 28.8 grains of water, my cases hold 30.4 grains of water. If the smaller case capacity of 28.8 were used with the same charge of 26.1 grains of powder the chamber pressure would be 61,938 psi and not 54,021 psi as listed below.

Also note that the max load for a AR15 would be the +04.0 load at 61,815 psi due to the higher pressure loading.

Cartridge : .223 Rem. (SAAMI)
Bullet : .224, 55, Hornady V-MAX FB 22271-72
Useable Case Capaci: 27.380 grain H2O = 1.778 cm³
Cartridge O.A.L. L6: 2.260 inch = 57.40 mm
Barrel Length : 20.0 inch = 508.0 mm
Powder : Hodgdon H335

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 76 20.88 2533 784 27857 6904 86.5 1.175
-18.0 78 21.40 2596 823 29738 7135 87.9 1.145
-16.0 80 21.92 2660 864 31749 7360 89.3 1.116
-14.0 81 22.45 2723 905 33903 7578 90.6 1.088
-12.0 83 22.97 2786 948 36208 7790 91.8 1.061
-10.0 85 23.49 2850 992 38678 7993 92.9 1.032
-08.0 87 24.01 2914 1037 41325 8186 94.0 1.001
-06.0 89 24.53 2977 1082 44167 8370 95.0 0.971
-04.0 91 25.06 3041 1129 47218 8543 95.9 0.943 ! Near Maximum !
-02.0 93 25.58 3104 1177 50497 8703 96.7 0.916 ! Near Maximum !
+00.0 95 26.10 3167 1225 54021 8852 97.4 0.889 ! Near Maximum !
+02.0 97 26.62 3231 1275 57782 8987 98.1 0.863 !DANGEROUS LOAD-DO NOT USE!
+04.0 99 27.14 3293 1325 61815 9107 98.6 0.839 !DANGEROUS LOAD-DO NOT USE! (max AR15 load)
+06.0 100 27.67 3356 1376 66154 9213 99.1 0.815 !DANGEROUS LOAD-DO NOT USE!
+08.0 102 28.19 3419 1427 70828 9303 99.5 0.792 !DANGEROUS LOAD-DO NOT USE!
+10.0 104 28.71 3481 1480 75870 9376 99.7 0.770 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 95 26.10 3321 1347 64780 8765 100.0 0.824 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 95 26.10 2964 1073 43873 8492 90.8 0.973

casecap_zpsb0f5b356.jpg
 
All the information in the white blocks below will effect chamber pressure, bullet weight, shape, case capacity, seating depth etc. will change the chamber pressure, and this is why the load data varies.

QL_zps0d854af9.jpg


Then you have to factor in barrel friction, below a button rifled barrel throat.

Throat-1-C-RS.jpg


Same barrel two inches from the muzzle.

6inchesfrommuzzle-2.jpg


Then you have custom made hand lapped barrels as smooth as a babies bottom.

custom.jpg
 
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X2 for "Quickload". It is very much worth the price IMHO, and is unique in that it teaches the user how marginal component/brand changes affect overall results and to what degree. Empirically, does it predict my results with 100% accuracy ? No, but it doesn't need 100% accuracy in that regard in order to be a highly effective tool. To those getting into reloading, I'd suggest you acquire "Hodgdon's free on line manual", "Lyman's 49th", and "Quickload" in that order. You'll be sorted, as far as loading data is concerned, for a very long time.
 
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